As well known to those skilled in the art, a conventional three-dimensional moving image photographing device for video cameras uses two video cameras to photograph right and left moving images of an object. The right moving image of the object is photographed using one of the video cameras arranged at the right side of the object, and the left moving image of the object is photographed using the other video camera arranged at the left side of the object. The photographed right and left moving images of the object are finally integrated. The conventional three dimensional moving image photographing device has a disadvantage in that it essentially requires two cameras each having various accessories, and in that it is difficult and takes much time to integrate the moving images.
An adapter for a three-dimensional moving image photographing device has been proposed in order to eliminate the aforesaid disadvantage, which has been invented by the inventor of the present application and is disclosed in Korean Unexamined Patent Publication No. 2000-24767. The disclosed adapter for the three-dimensional moving image photographing device comprises an adapter housing 18 having two liquid crystal shutter units 60 and 70 mounted therein for alternately photographing right and left moving images of an object 100, as shown in FIG. 5. A photographing lens 12 is arranged in between a second light axis A2, along which the right moving image of the object 100 passes, and a third light axis A3, along which the left moving image of the object 100 passes. In the adapter housing 18 is disposed a second total reflecting mirror 42, which is inclined at an angle of 45 degrees relative to the second light axis A2. Consequently, the moving image of the object 100 having passed through a concave lens 37 along the second light axis A2 is totally reflected by the second total reflecting mirror 42. In the adapter housing 100 is also disposed a third total reflecting mirror 43, which is inclined at an angle of 45 degrees relative to the third light axis A3. Consequently, the moving image of the object 100 having passed through another concave lens 37 along the second light axis A3 is totally reflected by the third total reflecting mirror 43. On a light axis A1 of the photographing lens 12 are disposed a half-reflecting minor 80 and a first total reflecting mirror 41. With the above-stated construction, the right moving image reflected by the second total reflecting mirror 42 is also reflected by the first total reflecting mirror 41 disposed on the light axis A1 of the photographing lens 12, and then enters the photographing lens 12. Similarly, the left moving image reflected by the third total reflecting mirror 43 is also reflected by the half-reflecting mirror 80 disposed on the light axis A1 of the photographing lens 12, and then enters the photographing lens 12. The liquid crystal shutter unit 60 is interposed between the half-reflecting minor 80 and the second total reflecting mirror 42 for allowing the moving image having been introduced along the second light axis A2 to enter the photographing lens 12 or stopping the moving image having been introduced along the second light axis A2 from entering the photographing lens 12. Similarly, the liquid crystal shutter unit 70 is interposed between the half-reflecting mirror 80 and the third total reflecting mirror 43 for allowing the moving image having been introduced along the third light axis A3 to enter the photographing lens 12 or stopping the moving image having been introduced along the third light axis A3 from entering the photographing lens 12. Consequently, while the fight moving image of the object 100 having been introduced along the second light axis A2 enters the photographing lens 12, the liquid crystal shutter unit 70 is closed off so that the left moving image of the object 100 having been introduced along the third light axis A3 does not enter the photographing lens 12. On the other hand, while the left moving image of the object 100 having been introduced along the third light axis A3 enters the photographing lens 12, the liquid crystal shutter unit 60 is closed off so that the right moving image of the object 100 having been introduced along the second light axis A2 does not enter the photographing lens 12. In conclusion, one of the right and left moving images of the object 100 is photographed while the other is not photographed in order to obtain the three-dimensional moving images of the object 100.
In the aforesaid conventional adapter for the three-dimensional moving image photographing device, however, an entrance pupil point E is formed inside the three-dimensional moving image photographing device, as shown in FIG. 6. For this reason, the second total reflecting mirror 42 and the third total reflecting mirror 43 must be arranged in such a manner that they are spaced apart from the light axis A1 of the photographing lens 12 in the right and left directions, respectively, when a wide moving image having a wider picture angle, for example, a picture angle of 52 degrees, is to be photographed. Furthermore, it is necessary to greatly increase the sizes of the total reflecting mirrors, which causes the adapter housing having the total reflecting mirrors mounted therein to be increased in size.
Besides, in the conventional adapter the distance between the light axis A1 of the photographing lens 12 and the second light axis A2 is not equal the distance between the light axis A1 of the photographing lens 12 and the third light axis A3, as shown FIG. 6. The result is that the right and left moving images of the object 100 are different from each other, whereby distortion occurs in the resulting moving images comprised of the integrated right and left moving images of the object 100.